Inox Precision Injection Molding

InoxCast is dedicated to spplying high-precision injection molding of close-tolerance precision plastic parts and optical using a wide options of engineering resins. Through our years of experience and expertise, more and more program managers and engineers trusted InoxCast precision injection molding.

InoxCast precision injection molding helps engineers and programers to ensure program success and improve system manufacturability. Our company provides in-house mold and tool storage maintenance services and in-house services.

InoxCast precison injection molding is designed to produce specialized parts in most industries such as automotive, electronics, optics, medical devices, and more. Additionally, it can be used as replacements for precision metal parts, products where small form factors are crucial, and advanced technical devices.

In China, we are experts in fabricating solutions with leading-edge technology and excellent partnership to a global network of suppliers. Our precision injection molding is popular in the marketplace for its advantageous features.

InoxCast Precision Injection Molding Advantages:

• efficient production
• strenght
• complex designs
• reduced cost

Inox is your precision injection molding specialists from mold design, part design, technology, and material selection. Our expertise helps to make high-quality and more efficient solutions across all stages of a product’s lifstyle.

Our expertise in precision injection molding improves the longevity and reliability of the manufacturing process.

Whether you need to import precision injection molding to support your business, InoxCast is the best place to count on. Our capabilities help you in business progress.

For more information about InoxCast precision injection molding, please don’t hesitate to message us today!

Precision Injection Molding: The Ultimate Guide

If you have any question on precision injection molding, you will find the answer right here.

So, keep reading to learn more.

1.  What Is Precision Injection Molding?

Precision injection molding is the size of the final molded product after injection at high precision.

It relies on the quick manufacture of plastic parts with sophisticated shapes that may replace metal parts of high precision.

precision injection molding

2.  What Elements Need Controlling During Precision Injection Molding?

Several elements require control in precision injection molding.

These include the strict control of the following:

• Selection of materials
• Design of the mold
• Injection molding process
• The technical level of operators

3.  What Is The Concept Behind Precision Injection Molding?

The concept behind injection molding varies from conventional injection molding.

Precision injection molding relies on the quick manufacture of polymer substances.

Furthermore, it will use precise plastic components that will replace the high precision metal components in several industrial applications.

4.  What Characteristics Will You Find In A Precision Injection Molding?

There are various characteristics of a precision injection molding and they include the following:

• The size of the components has small tolerance and high precision levels, meaning they contain a highly precise dimensional limit
• It adopts the process of precision injection molding
• The final product weight has high and repeatable accuracy and needs a day, month, and years of dimensional stability
• Molded materials are rigid and good with a high degree of finish, precise dimensional of the cavity, and position between templates
• Ensure selection of suitable materials that you will use in high precision injection
• Using a precision injection molding machine that replaces a conventional injection molding machine

5.  What Principles Will You Use To Select Materials For Precision Injection Molding?

There are various requirements you need when selecting the materials suitable for the process of precision injection molding.

These include the following:

• A broad range of adaptations to different environmental conditions
• Suitable creep resistance
• The mechanical strength needs to be high
• It should have a suitable dimensional stability

6.  What Types Of Materials Will You Use In Precision Injection Molding?

The different types of materials suitable for use in precision injection molding include the following:

• POM and CF [carbon fiber reinforced] or GF [glass enhancement]

This kind of material has many favorable characteristics such as:

1. Suitable creep resistance
2. Weatherability
3. Good fatigue resistance
4. Suitable dielectric features
5. It is hard to burn
6. Easily release lubricants

• PBT reinforced polyester

This kind of material has a short molding duration.

The time to form is described as PBT ≤ POM ≈ PA66 ≤ PA6.

• PA and glass fiber reinforced PA66

This kind of material has the following characteristics:

1. The flow performance is good
2. Strong impact resistance
3. It has a strong wear resistance
4. These materials can form products with a wall thickness of around 0.4mm

PA66 has a glass fiber reinforcement that has suitable heat resistance with a melting point of about 250 degrees Celsius.

precision injection molding

The only limitation to it is that the material is hygroscopic meaning you should humidify it once you complete some molding processes.

• PC and GFPC

These materials have the following features:

1. Suitable wear resistance
2. It has enhanced rigidity
3. The dimensional stability is good
4. Weatherability
5. Suitable molding
6. Flammability

7.  How Does Precision Injection Molding Work?

Here are the basic steps you will conduct during precision injection molding:

Closing of the mold

The precision injection molding cycle timer will start when you close the mold.

Injection

Once you heat the plastic, you will inject it inside the mold.

As the molten plastic enters the mold, air will escape via vents that are in the injection pins as well as the parting lines.

To ensure that the mold is sufficiently filled, you will use runners, gates, and vents.

Cooling

Once you fill the mold, the component starts cooling for an accurate time frame until the entire material hardens.

The time you require to cool the component relies on the resin you are using and the thickness of the component.

Every mold has a design with internal cooling lines or heating lines.

In these lines, water cycles through the mold, and this assists in maintaining a constant temperature level.

Resin Plasticizing

When the molded part is cooling, the barrel screw will retract.

Concurrently, it will draw a new resin plastic inside the barrel out from the hopper.

Heater bands will maintain the correct temperature within the barrel for the resin you are using in the process.

Ejection

In this step, the mold will open and the ejector rod will move the ejector pins in a forward motion.

The component will fall into a bin that is below the mold for collection purposes.

7.  What Factors Will Affect Shrinkage In Precision Injection Molding?

The shrinkage of parts during precision injection molding is affected by the following factors:

• Heat contraction
• Phase change contraction
• Orientation contraction
• Compression contraction

The definition of thermal shrinkage is the thermal physical properties of molding and mold materials.

When the temperature of the mold is high, the product temperature is high, and the shrinkage rate increases.

For this reason, ensure the temperature of the precision injection mold is not very high.

Phase change contraction occurs due to the crystallization of crystalline resins and polymer crystallization during the orientation phase because of volume reduction.

8.  What Factors Will Influence The Rate Of Shrinkage Of Molds In Precision Injection Molding?

Several factors will affect how shrinkage will happen during precision injection molding.

Some of these factors include the following:

• Orientation
• Pressure of resins
• Speed of injection
• Temperature of resin
• Time for cooling
• Temperature of mold
• Injection time
• The cross-sectional area of the gate
• Wall thickness of the product
• Enhancement of materials containing the basin

9.  What Are The Reasons As To Why You Should Use High Pressure In Precision Injection Molding?

A precision injection molding should happen at high-pressure levels because of the following reasons:

• To enhance the quality and accuracy of the precision products, the injection pressure highly influences the rate of shrinkage of the forming products.

Furthermore, the rate of product shrinkage is almost nil when the precision injection pressure attains 392 MPa.

In this scenario, the environment and the mold control will affect the precision of the final product.

Following experiments, if you increase the injection pressure from 98 MPa to 392 MPa, mechanical strength will increase by between 3% and 33%.

• The thickness of the walls of precision injection parts can be lowered and you can increase the forming length.

For instance, you can form products with a wall thickness of between 1.2 mm and 0.8 mm with pressure levels of 177 MPa with ordinary equipment.

When using precision injection molding, you can attain a wall thickness of between 0.15 mm and 0.6 mm at 392 MPa.

Also, you can make a longer ultra-high pressure injection machinery than the products.

• When you improve the injection pressure, you can enhance the efficiency of the rate of injection.

There are two ways you can use to attain such an injection rate.

First, you can increase the maximum injection pressure of the system.

Second, you can enhance the screw features and the ratio of length to diameter.

Furthermore, precision injection machines have a high injection rate.

10.  How Can You Prevent Deformations From Forming In Precision Injection Molding?

The formations of deformations happen when there is uneven shrinkage due to internal stress.

For this reason, it is vital to prevent uneven shrinkage from occurring within the mold.

If you have circular gears containing holes within the gear center, you can offer a gate at the center part.

However, ellipses will form when there is a large shrinkage difference rate between the resin’s vertical direction and direction of flow.

Ensure you set the gate at either 3 or 6 points when you need the roundness to have a higher rate of accuracy.

However, you should put full attention to the gate balance.

When you use the side of the gate, a 3-point gate increases the internal diameter of cylindrical products.

If gate marks are not used on the outer and end surfaces, minimally and uniformly using internal multi-point gates can attain a suitable outcome.

11.  What Factors Will Determine The Dimensional Accuracy Of The Mold In A Precision Injection Molding?

The dimensional accuracy of the molds in precision injection molding relies on the following aspects:

• Mold accuracy
• Formation of shrinkage rate
• Environmental elements like temperature, humidity, and fluctuating conditions

12.  How Will You Save Money When Using Precision Injection Molding?

Here are ways you can save costs when employing precision injection molding:

• Determine the mold area needing precision

Since precision injection molding is costly, be certain of what parts need tight tolerances.

For instance, certain parts of a component may not require tight tolerance levels and hence do not require precision injection molding.

• Select plastic materials containing low shrinkage

The plastic you select will determine if you can conduct precision molding.

For instance, the shrinkage rate of polypropylene ranges between +/-0 .014″ and +/- 0.022″.

This range is wide thus you cannot accurately attain high tolerance limits.

Materials such as Acrylonitrile butadiene styrene [ABS] have a narrower shrinkage thus suitable for attaining tighter tolerances.

Adding glass or filler resins such as mica or carbon fiber assists you in attaining higher tolerances with plastic materials.

This minimizes shrinkage and warp as if offers more structure.

• Select suitable manufacturers with high tool precision

The process of making parts with tight tolerances starts with a high-precision mold.

Plastic components that are not alike mean your products will be dissimilar.

A precise mold makes sure no variations exist between every mold.

Select manufacturers with an understanding of slow, steady processes when constructing high-precision tooling.

13.  What Are The Advantages Of Precision Injection Molding?

The innovation of precision injection molding is making more businesses rely on it when making precise parts.

Furthermore, they enjoy the technical application of precision injection molding and enjoy the advantages of high and cost-effective volume productions.

Precision injection molding offers the following advantages:

• Efficient production

Precision injection molding is fast enabling you to make many parts from one mold.

• Strength

Using fillers and other materials will enhance the strength of the plastic while minimizing costs.

• Complex designs

It enables you to make parts with complex configurations and high detail levels at high volumes.

• Lower costs

Applying automation with CNC machinery assists in lowering labor costs while enhancing production.

Automation enables you lower recurring labor costs as the machine can operate independently once you input the precision injection molding parameters.

14.  How Will You Minimize Errors When Making Molds In Precision Injection Molding?

For you to maintain a high mold accuracy, you need a high wear resistance which means you need quenching.

The quenching die precision can go up to 0.01 mm while using grinding and EDM machinery.

Also, be keen to increase the wear of the electrode when conducting red die machining.

Furthermore, prevent fluctuations of the mold by ensuring proper positioning of sliding components in every cycle.

Worn sliding parts with fire to maintain a high level of accuracy.

15.  What Are The Applications Of Precision Injection Molding?

Precision injection molding finds its application in the following areas:

• Electronic industries
• Automotive industries
• Medical devices
• Optic devices, etc.

16.  What Are The Traits Of A Precision Injection Molding Machine Relating To Control?

These controls include:

• Multi-level position
• Multi-stage back pressure
• Multi-stage pressure protection
• Multi-stage speed
• Multi-stage screw speed
• Multi-level injection feedback

17.  What Are The Common Defects In Molding When Using Precision Injection Molding?

Some defects you may encounter during precision injection molding include the following:

• Vacuum holes
• Short shot
• Bubbles
• Weld marks
• Split flying edge materials
• Flow marks
• Mold adhesions
• Silver back wires
• Shrinkage distortion
• Surface blowholes
• Charred black strips
• Albinism
• Cracking
• Bend deformations

18.  Do You Need Hydraulic Systems In Precision Injection Molding?

Yes, hydraulic systems are important in the oil circuit system as they will separate oil from the injection path.

Also, due to the speed of prediction injection molding, will emphasize the reaction speed of hydraulic systems.

hydraulic system

19.  What Are Some Of The Structural Features You Will Find In A Precision Injection Molding Machine?

These include:

• The speed of opening and closing of dies is fast, at about 60 nm/s
• Parallelism of templates that are fixed and moving has a control range of between 0.05 mm to 0.08 mm due to high injection pressure
• Plasticizing components like material barrels, check rings, screws, etc. have a strong plasticizing capacity
• Protection of dies with low pressure and control of clamping forces as it affects dimensional tolerances

20.  What Should You Do When You Experience Molding Flash In Precision Injection Molding?

Conduct the following:

• Lower the mold temperature of the injection pressure when they are too high
• Repair through machining the worn-out guide pins or pin holes
• Clean the surface of the mold to eliminate any unwanted objects or impurities
• Use a large precision injection mold when the force of the closing surface is insufficient

21.  What Options Do You Have When The Parts You Are Molding In Precision Injection Molding Have Weld Marks?

These include:

• Change the gate position if you notice the gate location is not properly set
• Add a cold feed hole when no cold material holes exist in the mold
• Clean the cavity surface to eliminate impurities
• Raise die and barrel temperature when the mold and melting material temperature is very low
• Speed up the injection speed if it is too low
• Eliminate or enhance the mold exhaust unit if you have highly volatile content in the raw materials or you have a bad mold exhaust
• Improve the filling performance of gating units to enhance the smooth flow of molten material within the cavities

22.  What Should You Understand When Choosing Precision Injection Molding To Make Your Products?

These include:

• Area of precision

These include aspects such as:

1. Issues with tolerance
2. Material selection
3. Injection technique

• Choosing precision machines

Ensure the machine can apply high pressure to enhance the overall quality of the final product.

More Resources:

Plastic Injection Molding

Metal Injection Molding

Die Casting

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